Republicans vs. Democrats vs. Libertarians.

What's the difference? Why can't the libertarian party get it together? That would be cool. If we had Republicans and Libertarians vying for Democrat acreage, what might we grow there? Is there a difference between Democrats and Republicans? I think there are stark differences. Could Republicans learn some lessons from the Libertarians? OMG yes. Could the Democrats learn from both of these or do they look to another?